[PATCH v3 10/11] PCI: rockchip: Don't advertise MSI-X in PCIe capabilities

From: Rick Wertenbroek <rick.wertenbroek@gmail.com>
To: alberto.dassatti@heig-vd.ch
Cc: damien.lemoal@opensource.wdc.com, xxm@rock-chips.com,
	"Rick Wertenbroek" <rick.wertenbroek@gmail.com>,
	"Shawn Lin" <shawn.lin@rock-chips.com>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Rob Herring" <robh@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Johan Jonker" <jbx6244@gmail.com>,
	"Brian Norris" <briannorris@chromium.org>,
	"Caleb Connolly" <kc@postmarketos.org>,
	"Corentin Labbe" <clabbe@baylibre.com>,
	"Arnaud Ferraris" <arnaud.ferraris@collabora.com>,
	"Lin Huang" <hl@rock-chips.com>,
	"Judy Hsiao" <judyhsiao@chromium.org>,
	"Hugh Cole-Baker" <sigmaris@gmail.com>,
	linux-pci@vger.kernel.org, linux-rockchip@lists.infradead.org,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v3 10/11] PCI: rockchip: Don't advertise MSI-X in PCIe capabilities
Date: Tue,  4 Apr 2023 10:24:23 +0200	[thread overview]
Message-ID: <20230404082426.3880812-11-rick.wertenbroek@gmail.com> (raw)
In-Reply-To: <20230404082426.3880812-1-rick.wertenbroek@gmail.com>

The RK3399 PCIe endpoint controller cannot generate MSI-X IRQs.
This is documented in the RK3399 technical reference manual (TRM)
section 17.5.9 "Interrupt Support".

MSI-X capability should therefore not be advertised. Remove the
MSI-X capability by editing the capability linked-list. The
previous entry is the MSI capability, therefore get the next
entry from the MSI-X capability entry and set it as next entry
for the MSI capability. This in effect removes MSI-X from the list.

Linked list before : MSI cap -> MSI-X cap -> PCIe Device cap -> ...
Linked list now : MSI cap -> PCIe Device cap -> ...

Signed-off-by: Rick Wertenbroek <rick.wertenbroek@gmail.com>
---
 drivers/pci/controller/pcie-rockchip-ep.c | 15 +++++++++++++++
 drivers/pci/controller/pcie-rockchip.h    |  5 +++++
 2 files changed, 20 insertions(+)

diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index 924b95bd736c..20c768287870 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -510,6 +510,7 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev)
 	size_t max_regions;
 	struct pci_epc_mem_window *windows = NULL;
 	int err, i;
+	u32 cfg_msi, cfg_msix_cp;
 
 	ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
 	if (!ep)
@@ -584,6 +585,20 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev)
 
 	ep->irq_pci_addr = ROCKCHIP_PCIE_EP_DUMMY_IRQ_ADDR;
 
+	cfg_msi = rockchip_pcie_read(rockchip, PCIE_EP_CONFIG_BASE +
+				     ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
+
+	cfg_msi &= ~ROCKCHIP_PCIE_EP_MSI_CP1_MASK;
+
+	cfg_msix_cp = rockchip_pcie_read(rockchip, PCIE_EP_CONFIG_BASE +
+					 ROCKCHIP_PCIE_EP_MSIX_CAP_REG) &
+					 ROCKCHIP_PCIE_EP_MSIX_CAP_CP_MASK;
+
+	cfg_msi |= cfg_msix_cp;
+
+	rockchip_pcie_write(rockchip, cfg_msi,
+			    PCIE_EP_CONFIG_BASE + ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
+
 	rockchip_pcie_write(rockchip, PCIE_CLIENT_CONF_ENABLE, PCIE_CLIENT_CONFIG);
 
 	return 0;
diff --git a/drivers/pci/controller/pcie-rockchip.h b/drivers/pci/controller/pcie-rockchip.h
index 1558eae298ae..a21070ea7166 100644
--- a/drivers/pci/controller/pcie-rockchip.h
+++ b/drivers/pci/controller/pcie-rockchip.h
@@ -226,6 +226,8 @@
 #define ROCKCHIP_PCIE_EP_CMD_STATUS			0x4
 #define   ROCKCHIP_PCIE_EP_CMD_STATUS_IS		BIT(19)
 #define ROCKCHIP_PCIE_EP_MSI_CTRL_REG			0x90
+#define   ROCKCHIP_PCIE_EP_MSI_CP1_OFFSET		8
+#define   ROCKCHIP_PCIE_EP_MSI_CP1_MASK			GENMASK(15, 8)
 #define   ROCKCHIP_PCIE_EP_MSI_FLAGS_OFFSET		16
 #define   ROCKCHIP_PCIE_EP_MSI_CTRL_MMC_OFFSET		17
 #define   ROCKCHIP_PCIE_EP_MSI_CTRL_MMC_MASK		GENMASK(19, 17)
@@ -233,6 +235,9 @@
 #define   ROCKCHIP_PCIE_EP_MSI_CTRL_MME_MASK		GENMASK(22, 20)
 #define   ROCKCHIP_PCIE_EP_MSI_CTRL_ME				BIT(16)
 #define   ROCKCHIP_PCIE_EP_MSI_CTRL_MASK_MSI_CAP	BIT(24)
+#define ROCKCHIP_PCIE_EP_MSIX_CAP_REG			0xb0
+#define   ROCKCHIP_PCIE_EP_MSIX_CAP_CP_OFFSET		8
+#define   ROCKCHIP_PCIE_EP_MSIX_CAP_CP_MASK		GENMASK(15, 8)
 #define ROCKCHIP_PCIE_EP_DUMMY_IRQ_ADDR				0x1
 #define ROCKCHIP_PCIE_EP_PCI_LEGACY_IRQ_ADDR		0x3
 #define ROCKCHIP_PCIE_EP_FUNC_BASE(fn) \
-- 
2.25.1

